What are the three primary types of pollutants found in water?

The identification of nutrients, sediments, and chemicals as the three primary types of pollutants in water is founded on their significant impact on aquatic ecosystems and human health. Nutrients, particularly nitrogen and phosphorus, can lead to eutrophication, resulting in harmful algal blooms that deplete oxygen in the water and harm fish and other aquatic organisms. Sediments can smother habitats, reduce light penetration, and carry other pollutants, while chemicals encompass a wide range of harmful substances, including industrial discharges, pharmaceuticals, and other toxicants that can disrupt ecosystems and pose health risks.

Each of the other options presents valid pollutants but does not encompass the primary categories as comprehensively. Heavy metals, bacteria, and plastics, for example, are indeed pollutants of concern but may not cover the broader categories of nutrients or chemicals. Similarly, the combination of pesticides, sediments, and organic matter focuses on specific types of pollutants but lacks the generality of chemicals and includes sediments already mentioned in the correct answer. Finally, while nutrients, oils, and trash are relevant, the term "chemicals" in the correct answer is a broader and more encompassing category that provides a clearer framework for understanding water pollution.